There is a need for a convenient way to dispose of compounds such as drugs, injectables, and other pharmaceutical compounds in a way such that they do not contaminate waterways and/or eventually return unused and unprocessed pharmaceuticals to the public water supply. Wastewater contamination is an important issue, especially in hospital, dental, home care and other settings where pharmaceuticals are commonly discarded. Healthcare workers are known to dispose of pharmaceuticals incorrectly, often unintentionally, which can lead to contaminated waste water. In the hospital, dental, home care and other settings, items that contain toxic chemicals are routinely poured down sinks. Since most waste water treatment facilities do not specifically treat for these chemicals, this can lead to pollution problem and to drugs making their way into public water supplies. In some instances, disposal of chemicals down sinks may lead to fines for violating EPA regulations.
The EPA has identified 1,500 publicly owned treatment works (“POTWs”) that are required to have a pretreatment program, and another 13,500 facilities that are not required to have a pretreatment program. Given the breadth of potential contaminants, the EPA focused on the following waste materials: mercury, primarily from dental facilities, but also from some medical equipment devices; and unused pharmaceuticals. Unused pharmaceuticals include animal and human drugs. Recent estimates are that over 200 million pounds of unused pharmaceuticals are dumped into the nation's wastewater system. They include wasted pills, excess liquid formulations (injectables and swallowed) and spilled biohazards. While the EPA and other regulators have best management practices in place, there is no measured data on the amount of unused pharmaceuticals entering POTWs. Current best management practices include: incineration or disposal in a solid-waste landfill. However, most pharmaceuticals are still disposed by being poured down a sink.
In its August 2008 Health Services Industry Study, (“EPA 2008 Study”) EPA stated that, “52,089 hospitals and [other medical facilities] are potentially discharging spent pharmaceuticals” into the US water system, and “most of the facilities that discharge wastewater must discharge it indirectly to municipal sewer systems.” The EPA 2008 Study is incorporated herein by reference. The report goes on to say that “a number of studies conducted over the past 10 years suggest detection of pharmaceutical compounds in treated wastewater effluent, streams, lakes, seawater, and groundwater, as well as in sediments and fish tissue.” The EPA is being pushed to solve this growing problem.
The EPA 2008 Study notes at p.4-1 and following that The Drug Enforcement Agency (“DEA”) enforces the Controlled Substances Act (“CSA”). The goal of the CSA is to provide a closed distribution system for controlled substances. As part of this closed distribution system, DEA prohibits the return of controlled substances from end-users to any DEA registrant (including pharmacies, hospitals, clinics, researcher, or practically any other facility or individual), or transfer to anyone except, in certain cases, a law-enforcement agent. Disposal of controlled substances by DEA registrants is carefully regulated to ensure that the substance is destroyed or rendered unrecoverable. One acceptable method of destruction is flushing controlled substances into the wastewater. DEA registrants have the following options for disposing of controlled substances:                They can return the controlled substance to the pharmaceutical manufacturer.        They can transfer the controlled substances to a reverse distributor to return them to the manufacturer or dispose of them. Hospitals typically have pre-existing arrangements with hazardous waste disposal firms and therefore do not need to make special arrangements for disposal of unused pharmaceuticals as hazardous waste. These disposal firms pick up the materials from the hospital and handle proper disposal.        They can dispose of the controlled substances under the procedures outlined in 21 CFR 1307.21, which provides that a DEA Special Agent in Charge can authorize for the disposal of the controlled substance in several ways.        
In the EPA 2008 Study at p.6-1, EPA asserts that health service facilities have three disposal options for pharmaceuticals that are identified as waste and which cannot be returned to manufacturer for credit: (1) disposal to sewer; (2) incineration (RCRA incineration or low temperature incineration); and (3) disposal to landfill. These disposal mechanisms, however, follow the option of returning materials to the manufacture to be recycled/recovered for reuse.
Common pharmaceuticals that are considered “hazardous wastes” under the Resource Conservation and Recovery Act (“RCRA”) include epinephrine, nitroglycerin, warfarin, nicotine, and many chemotherapy agents. These waste items are subject to unique and expensive disposal requirements, since the EPA regulates the generation, storage, transportation, treatment, and disposal of any pharmaceutical waste defined as hazardous waste by RCRA. The EPA is considering an expansion of these regulations by adding hazardous pharmaceutical waste to the Universal Waste Rule and published its intent in the Federal Register on Dec. 2, 2008. Hospitals and other health care providers in several states have faced significant fines associated with violations of RCRA and EPA requirements. Fine amounts can be large and vary by state. Facilities in Nebraska, Minnesota, Florida, and other states have already been subject to inspections and subsequent fines, sometimes in excess of $100,000. For example, in early 2005, USEPA Region 2 (New York, New Jersey, the Virgin Islands, and Puerto Rico), noted that of the 480 hospitals in the region, 44 have been inspected to date, resulting in 22 enforcement actions. Nine formal enforcement actions resulted in proposed fines of more than $900,000 and six settlements were reached for a total of more than $400,000 in fines. The problem addressed by the present invention is large, and its priority to regulators is increasing and likely to continue rising in importance.
An article on the impact and risks of drugs in the water system was released by the Associated Press on Mar. 10, 2008. The story was picked up by CNN, USA Today, Fox News and many national and international news outlets. The Denver Post ran a follow up article on Sep. 11, 2008 confirming that municipalities are finding most of their systems have detectable levels of narcotics, hormones and other potentially dangerous contaminants. These articles have had the effect of energizing the public and lobbyists around the issue of water contamination. As a result, relevant agencies are now working together to identify possible solutions and agree on best practices for handling drugs prior to or once in the water system.
A variety of treatment/processing options are available to treat wastewater containing unused pharmaceuticals. These processing options include chemical or physical adsorption, ion exchange, membrane filtration, electrodeionization, photo ionization, and other similar technologies. Treatment can include destruction of target compounds by exposing them to appropriate chemicals. Destruction can be accomplished by exposing organic materials to acids, bases, oxidizers, or reducing agents. Oxidizers, for example, may include peroxide, chlorine (gaseous or in solution), and various other chemicals and may be derived in-situ from known processes.
Activated carbon, coal or resin beads remove oxidizers from a solution by a physical or chemical adsorption mechanism and remove dissolved organics by physical adsorption. Activated carbon can be used as granules or in monolithic block form.
Ion exchange works by exchanging hydrogen ions for cationic contaminants and hydroxyl ions for anionic contaminants in an aqueous solution. Ion exchange resin beds are made up of small beads through which the solution passes. After a period of time, cations and anions from the solution will replace most of the available hydrogen and hydroxyl sites in the resins and the resin bed will need to be replaced or regenerated. Ion exchange will only remove ionic compounds from the water. Dissolved organics can foul the ion exchange beads, decreasing their capacity. Where organically and inorganically pure water is needed, the combination of reverse osmosis or carbon filtration followed by ion exchange is particularly effective.
There are multiple names for filtration using microporous membranes including, but without limitation, microporous filtration, reverse osmosis (RO), ultra-filtration. All of these filtration technologies have in common the use of a membrane with tiny pores through which water may pass, but which prevents the passage of particles or solutes of a particular charge or size. Reverse osmosis is based on the fact that a chemical potential gradient can be eliminated by forcing a solution through a membrane. Water, driven by an osmotic pressure, a force caused by the concentration difference, passes through the membrane into the concentrated solution. The flow of water continues until the concentrated solution is diluted to approximately the same concentration as the formerly dilute solution (i.e., the chemical potential gradient is eliminated). If a pressure greater than the osmotic pressure is applied to the higher concentration side of the membrane, the normal direction of osmotic flow is reversed, pure water passes through the membrane from the concentrated solution and is thus separated from its contaminants. Membrane materials include, but are not limited to polyamide thin film and cellulosic membranes. Thin-film composite membranes are commonly used, but the materials of which they are comprised vary greatly. Ultra-filtration uses a membrane very similar in design to reverse osmosis, except that the ultra-filter pores are slightly larger, from 0.001 to 0.02 micron. The details of how to apply filtration using membranes will vary depending on the purity of effluent desired and the materials to be removed.
Electrodeionization (“EDI”) features a combination of ion exchange resin and ion-selective membranes. EDI is a refinement of electrodialysis (“ED”). The principle of ED is that water is purified in a cell containing two types of ion selective membranes (cation-permeable and anion-permeable) between a pair of electrodes. When an electric potential is applied across the cell, the cations in the water migrate towards the negatively charged cathode and the anions migrate towards the positively charged anode. The cations can pass through the cation-permeable membrane, but not through the anionic one and vice-versa. The net result is the movement of ions between chambers and the water in one section can become deionized while that in another section becomes concentrated. There is a practical limit to the purity than can be obtained by ED because of the prohibitively high electrical voltages required to drive ions through water of increasingly high purity. This problem is overcome in EDI technology by filling the spaces between the membranes with ion exchange resins. The resins provide a conductive flow path for the migration of ions, enabling deionization to be virtually complete and resulting in the production of high-purity water.
Photo-oxidation uses high intensity electromagnetic radiation (usually ultraviolet) to cleave and ionize organic compounds for subsequent removal by, for example, ion exchange cartridges. Radiation with a wavelength of 185 nm is most effective for the oxidation of organics.